In recent years, cosmetics have contained various powders. The types of powders are roughly classified into organic powders and inorganic powders, but recently, the market has seen many composite powders containing both organic and inorganic powders. Effects of cosmetics containing these powders include skin color adjustment, cover up of a blemish, a freckle and the like, adjustment of skin qualities, impartment of a color, impartment of brightness, sebum absorption, improvement of touch, prevention of ultraviolet rays and infrared rays, an anti-inflammatory activity, sedation, a massage effect, an effect of preventing the deterioration of makeup off the skin and the like. Meanwhile, demerits provided by incorporating powders into cosmetics include, mainly in case of inorganic powders, skin irritation caused by a powdery feeling on the skin, physical irritation caused when coated onto the skin, occurrence of chemical catalytic activity of powders and the like, occurrence of dry skin caused by the absorption of sweat or sebum of the skin by powders, a dull color given by wetting of powders with sweat or sebum, and the like.
Cosmetics containing powders include not only makeup products but also skin care products, sunscreen products, shampoos, rinses, hair tonics, hair growth promoters, cleansers, antiperspirants, bath products, and the like. It is proposed that the particulate surface of the powder incorporated into these products is coated with silicone compounds, fluorine compounds, esters, fatty acids, waxes, amino acids, peptides, lecithin, polyolefins, coupling agents, surfactants and organic compounds such as water-soluble polymers in order to maximize the functions of powders and presenting them in cosmetic effects. Among these coating agents, amino acids are one of many components making up the living body, and amino acids obtained by acylating the same, are expected to provide various physiological activities to the skin. The powders coated with the acylated amino acids are deemed to have effects such as improvement of a feeling in use, improvement of an adhesiveness to the skin, impartment of water repellency and water resistance, impartment of oil repellency, improvement of miscibility with oil components, improvement of duration of cosmetic effects, storage stability, dispersibility and UV-screening ability, excellent biocompatibility and the like, and many proposals have been made.
For example, it is reported that a powder coated with an N-acylated amino acid amide such as N-lauroyl-L-glutamic acid-α,γ-di-n-butyl amide has characteristics that it can impart a water repellency and has good skin adhesion,and a smooth aesthetic touch and also has good miscibility with oil components because of a high lipophilicity (refer to, for example, Japanese Patent Kokai Publication JP-A-1-172312 (pp. 3-6, Tables 1 and 2)).
It is reported that a powder coated with N-lauroyl-L-lysine is excellent in spreadability on the skin, primary as well as final aesthetic feeling, and also excellent in makeup duration over the course of time (refer to, for example, JP-A-9-208427 (pp. 3-6, Tables 3 and 4)).
Furthermore, there is a report about a powder that is double-coated with an acylated basic amino acid and a fat (for example, fatty acid) having an acid group (refer to, for example, JP-A-5-58842 (pp. 4-9)) This coated powder shows water repellency, prevents makeup from coming off due to sebum or the like, also improves spreadability of cosmetics on the skin and imparts good touch to the skin.
The present inventors have proposed powders coated with N-acyl-L-glutamic acid, N-acyl-N-methylglycine, N-acyl-N-methyl-β-alanine and salts thereof (refer to, for example, JP-A-58-72512 (pp. 4-6)). Cosmetics containing this powder have a function of protecting the skin, and have excellent adhesion to the skin, touch, and stability.
The present inventors have improved the powders coated with the above N-acylated amino acids, and have reported powders coated with mixtures containing N-acyl derivatives of at least 14 amino acids (refer to, for example, JP-A-2000-212041 (pp. 8-22, FIG. 1)). The powders have quite a smooth touch, and are good in feeling when applied to the skin or the hair and have excellent biocompatibility.
Cosmetics in general have an objective of making the skin clean and beautiful without impairing a physiological activity of healthy skin. Further, people wish to stay beautiful and young forever. Functional cosmetics that realize this hope have been required. To meet these requirements, cosmetics contain components having a skin care effect and components having an anti-aging effect. However, a coated powder that exhibits a good skin care effect, providing a moisturizing function, adjusting skin texture, and providing an anti-aging effect of improving the rough skin, has not been proposed.